The JIS standard defines that permanent marks such as alignment reference marks (for example, a pair of hidden marks) need to be applied to some spectacle lenses including a progressive power spectacle lens by using a method that prevents the marks from disappearing easily (for example, etching). Meanwhile, for example, a layout mark indicating a layout of a predetermined reference position such as a power measurement position is optionally provided for some products according to an agreement among manufacturers. Typically, the layout mark is provided by painting which can be removed and, for example, it is removed after process of cutting lens is applied. JP 4596454 B1 (hereinafter, regarded as “Patent Literature 1” for convenience) discloses a specific example of the spectacle lens provided with the layout mark of such a type.
The spectacle lens disclosed in Patent Literature 1 is a lens whose convex surface is formed as a progressive surface (hereinafter, regarded as “convex surface progressive power lens” for convenience). In the convex surface progressive power lens disclosed in Patent Literature 1, a pair of the hidden marks (permanent marks) is placed on the convex surface and the layout mark is painted on the same convex surface.